Combine first 3 ingredients; sprinkle over chicken. Coat a nonstick skillet with cooking spray; place over medium-high heat until hot. Add chicken; cook 3 to 5 minutes on each side or until browned. Remove chicken from pan, and set aside.
Add wine to pan; deglaze by scraping particles that cling to bottom. Combine flour and 1/4 cup milk, stirring until smooth; add to pan. Stir in remaining 1/2 cup milk and mustard. Cook over medium heat, stirring constantly, until thickened. Return chicken to pan. Bring to a boil; cover, reduce heat, and simmer 5 minutes or until chicken is done. To serve, spoon sauce over chicken.